Kaposi’s Sarcoma- Is your immunity strong enough to resist the cancer?

May 10, 2009

WHEN James, 85, went to a clinic after his skin had developed black patches, the doctor referred him to Mulago Hospital to test for kaposi’s sarcoma. <br>

By Juliet Waiswa and Lydia Lakwonyero

WHEN James, 85, went to a clinic after his skin had developed black patches, the doctor referred him to Mulago Hospital to test for kaposi’s sarcoma.

Kaposi’s sarcoma is a type of skin cancer that affects the elderly or any person with a weakened immune system.

It is mainly associated with people living with HIV/AIDS. The virus attacks the immune system, making it vulnerable to opportunistic diseases.

According to statistics from the Uganda Cancer Institute, Mulago Hospital, only one out of 10 people who are not HIV-positive suffer from the cancer.

In Uganda it is the most common cancer, accounting for four out of every 10 cancer diagnosis made at the Cancer Institute at Mulago Hospital.

It is a cancer mainly of the blood vessels and because the vessels exist everywhere in the body, any organ can be attacked.

A typical clinical feature of kaposi's sarcoma takes the form of lesions on the skin and mouth, usually with raised nodules that may appear red, purple, brown, or black, depending on one’s complexion.

Although the cancer mostly affects the skin or mouth, many times it grows in the intestines and lungs. In some people, it occurs in the eyes, bones or spinal cord.

The growth of these lesions ranges from very slow to explosively fast, almost plague-like. The skin lesions may disfigure a patient and consequently cause physical or psychological pain.

What causes kaposi’s sarcoma?
It is caused by the Human Herpesvirus type 8 (HHV-8), which is also known as kaposi’s sarcoma-associated herpesvirus (KSHV).

Although HHV-8 was discovered only recently, the virus has reportedly been circulating in humans for at least 10,000 years.

In contrast, HIV is thought to have been introduced into humans 50 to 75 years ago. This helps to explain why the cancer was known to occur long before the HIV epidemic.

While almost all people who have the cancer are infected with HHV-8, many, other than just those with the cancer, are also infected with the virus.

According to Dr. Victoria Walusansa, an oncologist at the Cancer Institute, in Uganda, about four out of 10 adults are infected with HHV-8. She says about 80% of the population could be infected with the virus.

Other parts of Africa also have a high frequency of HHV-8, which is about two or three out of 10 people.

Interestingly, while the HHV-8 infection is common in Africa, it is uncommon in other parts of the world such as the US, Europe, and Asia. It is not known why HHV-8 mostly affects Africans. Uganda reportedly has the highest infection rates in the world.

Dr. Miriam Laker, the coordinator of ARV-kaposi’s sarcoma (antiretroviral for the cancer), says a study carried out at the Infectious Disease Institute in Mulago attributes the high rate to habits only found among Ugandans.

“It is in Uganda where you find mothers chewing children’s food to soften it before giving it to them. Some mothers use saliva to lubricate a child’s anus during constipation and soothe wounds, or they mix herbs to treat certain ailments in children,” says Laker.

She says such habits increase the spread of HHV-8 that is known to thrive in body fluids, especially in saliva. Like many viruses, there is no cure for HHV-8. “It can only be detected at the blood bank,” she says.

Who is at risk?
Anybody infected with HHV-8 is at risk of suffering from the cancer. The virus, once contracted, stays dormant in the individual for life and only attacks when the opportunity strikes, in most cases, when a person’s immunity is weak.

This explains why HIV-positive people are at a higher risk of getting the cancer because the virus weakens their immune system.

An uncommon group of people who risk contracting the disease are those who undergo surgery that involves organ transplants. These may fall victim, as during surgery, the immune system is weakened for the body to accept the organ.

In this case, if the individual already has the causative virus or contracts it from the organ donor, one is at risk of getting the cancer.
It also applies to patients on immuno suppressive treatment.

If they have the HHV-8 virus, they are in danger of developing the cancer.

It should also be noted that sarcoma does not discriminate against sex or age; prevalence is as high in both men and women.

How it is spread
The only known link to the spread of the cancer is through the causative virus, HHV-8. It is found only in humans and cannot be picked from animals or the environment.

Scientists say HHV-8 is spread through exchange of body fluids. HHV-8 can be found in blood and genital secretions, but is commonly found in, and spread through saliva. It is known that most infection occurs in childhood.

About three out of 10 Ugandans are infected with HHV-8 by the age of 12, with most infections occurring between the age of two and eight.

One out of 10 Ugandans become infected in their adult years. Other less common ways to contract HHV-8 are by sharing syringes and needles,.

A person with a strong immune system can ably contain the virus, keeping it in its dormant phase for the rest of their life unless the immune system weakens at some point, causing the cancer.

Treatment
The cancer can be treated at the Cancer Institute, using anti-retroviral treatment (ART) for mild cases and chemotherapy for acute cases.

This is why HIV/AIDS patients on ARVs stand a better chance of suppressing the virus.
However, it should be noted that kaposi’s sarcoma has no cure. Once one contracts it, he needs to stay on treatment permanently to suppress the disease.

There are instances where the disease is so much suppressed to levels where it cannot be detected physically or in the blood. However, such is only a state of remission, and should the patient stop treatment, the disease recurs.

This means progressive treatment has to be started all over again.
According to Walusansa, the cancer is not treated to cure, but to reduce replication as a means of controlling the disease. “It is like HIV/AIDS. You can only control it to help the patient live longer,” she says.

The disease can progress to stages where it cannot respond to any kind of treatment and in this case, there is nothing that can be done for the patient.

Symptoms
Black flat or dark brown spots, patches or round swellings. The swellings are usually not painful or itchy. In the early stages, they may be very small, but as they progress, they may become raised or develop into bigger patches.

The lesions may develop wounds and produce fluid. When the swellings occur on the legs, feet, arms or face, they could extend to the genitals.

If the cancer affects the lungs, it may cause a dry or bloody cough. A person may also run out of breath after a mild exercise.
l If it occurs in the intestines, it may cause one to vomit blood or pass blood with stool.

Among people who have it in the lungs or intestines, in most cases the skin is also affected. Dr. Miriam Laker, the coordinator of ARV-kaposi’s sarcoma, says: “The speed of development of the cancer varies from person to person.

In some people, it grows slowly, while in others it grows fast, with new spots occurring almost every week.

“In some people, the tumour grows in only one part of the body, while in others, it spreads to other body parts. The different pattern of the cancer in each person is one of the most striking aspects of the illness.

“We have free medical examination at every centre. When a suspected sufferer comes to us, we do a punch biopsy by taking a small piece of tissue from the lesion to confirm whether the person has the cancer or not,” she adds.


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